An Islamic website has posted a video of a US hostage Paul Johnson , with the threat to kill him.
The website names certain militants, seized in Saudi Arabia, and demands for them to be released. Otherwise, the US captive would be killed, according to the statement.
The video shows a blindfolded man who speaks out his name - Paul Johnson - who is an American defence employee that went missing several days ago. He was abducted last week in Saudi capital Riyadh.
The British press has recently reported that Russia was going to conduct a nuclear test either on the borders with Ukraine or in the Black Sea.